fs/ntfs3: disable readahead for compressed files

fs/ntfs3: disable readahead for compressed files

Reading large compressed files is extremely slow when readahead is enabled.
For example, reading a 4 GB XPRESS-4K compressed file (compression ratio
≈ 4:1) takes about 230 minutes with readahead enabled, but only around 3
minutes when readahead is disabled.

The issue was first observed in January 2025 and is reproducible with large
compressed NTFS files. Disabling readahead for compressed files avoids this
performance regression, although this may not be the ideal long-term fix.

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>